Governments around the world are being urged to get ready for a surge in temperatures and severe weather that could impact our health, ecosytems and economies and hit 1.5 degrees of global warming.
The World Meteoroligcal Organization warned on Tuesday that El Niño conditions have developed in the Pacific for the first time in seven years.
El Niño is a naturally occurring weather pattern that comes into play between every two and seven years on average.
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It is associated with warming sea surface temperatures as well as increased rainfall and warmer summers.
But global warming could be making the weather pattern more frequent says Maynooth University professor and climate expert John Sweeney which could drive the world over 1.5 degrees of global warming.
He told us: “The expectation is that not this year, but next year, the consequence of the El Niño will be the world will probably break through the 1.5 degree warming threshold.
“That’s of course the value we are contracted to try and avoid breaking through since the Paris Agreement.”
Temperatures could fall again when El Niño phases back to La Niña, which ended earlier this year.
But he added: “The effect of global warming is expected to increase the frequency of El Niño events such as we are having because the sea is getting warmer.
“It occurs when the trade winds fail,” he explained.
“The Pacific trade winds normally converge on the equator and blow water across towards the Australia area.
“The effect of that is to bring cold water up across the western side of South America so you get upwelling and nutrients coming to the surface.”
When El Niño, named for the Christ child as it usually happens around Christmas, occurs - Prof Sweeney says climate zones reverse.
“Instead of dry conditions on the western side of South America you get floods and heavy rainfall... and in Indonesia and Australia you get drought,” he added.
“We’re now facing into a whole suite of impacts associated with that reversal.”
In terms of what it does to us in Ireland, Prof Sweeney told us: “The linkages are quite weak... so we don’t need to get too uptight.
“We do tend to get colder winters in Northern Europe... [and] there are some tentative suggestions of an impact on rainfall.”
WMO Secretary-General, Prof Petteri Taalas, has also warned of the impact on the climate crisis.
A WMO report in May also said there’s a 66% likelihood the annual average near-surface global temperature between 2023 and 2027 will temporarily be more than 1.5°C above pre-industrial levels for at least one year.
He said: “The onset of El Niño will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean.
“The declaration of an El Niño by WMO is the signal to governments around the world to mobilize preparations to limit the impacts on our health, our ecosystems and our economies,” he added.
“Early warnings and anticipatory action of extreme weather events associated with this major climate phenomenon are vital to save lives and livelihoods.”
According to WMO’s State of the Global Climate reports, 2016 is the warmest year on record because of the “double whammy” of a very powerful El Niño and human-induced warming from greenhouse gases.
The effect on global temperatures usually plays out in the year after its development and so will likely be most apparent in 2024.
The average global temperature in 2022 was about 1.15 °C above the 1850-1900 average because of the cooling triple-dip La Niña.
WMO Director of Climate Services Prof Chris Hewitt said: “It is yet another wake up call, or an early warning, that we are not yet going in the right direction to limit the warming to within the targets set in Paris in 2015 designed to substantially reduce the impacts of climate change.”
Typical impacts
- Increased rainfall in parts of southern South America, the southern United States, the Horn of Africa and central Asia
- Severe droughts over Australia, Indonesia, parts of southern Asia, Central America and northern South America
- Fuelling hurricanes in the central/eastern Pacific Ocean
- Hindering hurricane formation in the Atlantic Basin
